MBF Healthcare Partners said in a brief statement Wednesday afternoon that it had "mutually agreed" with Universal not to proceed with the acquisition of certain assets of Universal. An MBF spokeswoman said there would be no further comment.

A Universal spokesman could not be reached for comment.

MBF had promised to invest enough to resurrect both the depleted reserves and poor quality ratings that have plagued Universal. It also had pledged to keep the insurer's headquarters and remaining 1,000 employees in downtown St. Petersburg.

Once among the fastest-growing companies in St. Petersburg, Universal Health Care has received poor quality marks from Medicare regulators and brought in fewer customers than expected during the fall Medicare enrollment. The company has stopped marketing its Medicare services in all areas as regulatory scrutiny has grown.

Regulators from Georgia and Ohio late last year prohibited the insurer from writing new policies, citing concerns about the company's relatively low reserves compared with its rising losses.

The Florida Office of Insurance Regulation has repeatedly declined to discuss whether any regulatory actions are being considered or say whether it has followed the lead of Georgia and Ohio by conducting its own investigation. An office spokeswoman cited Florida law, which assures confidentiality during investigations for insurers whose financial solvency, condition or soundness is being monitored.